# US 5,349,424 A · Thick walled heated belt fuser > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,349,424 A - Document ID: US5349424A - Status: Granted - Kind: A - Application number: 08/140,926 - Filed: 1993-10-25 - Granted: 1994-09-20 - Earliest claimed: 1993-10-25 - Assignees: Xerox Corporation - Inventors: Edul N. Dalal; Robert M. Jacobs - Web page: https://patentgrep.com/patent/US5349424A ## CPC - G03G 15/2064: {combined with pressure} - G03G 15/206: {Structural details or chemical composition of the pressure elements and layers thereof} - G03G 2215/2016: Heating belt - G03G 2215/2032: the belt further entrained around additional rotating belt support members - G03G 2215/2041: the fixing nip being formed by tensioning the belt over a surface portion of a pressure member - G03G: ELECTROGRAPHY; ELECTROPHOTOGRAPHY; MAGNETOGRAPHY ## Abstract A heated thick walled belt fuser for an electrophotographic printing machine. The belt is rotatably supported between a pair of rolls. One of the spans of the belt is in contact with a heating roll in the form of an aluminum roll with an internal heat source such as a quartz lamp. The belt is able to wrap a relatively large portion of the heating roll to increase the efficiency of the heat transfer. The second span of the belt forms an extended fusing nip with a pressure roll. The extended nip provides a greater dwell time for a sheet in the nip while allowing the fuser to operate at a greater speed. External heating enables a thick profile of the belt, which in turn allows the belt to be reinforced so as to operate at greater fusing pressures without degradation of the image. The thick profile and external heating of the belt also provides a much more robust design than conventional thin walled belt fusing systems. ## Claims ### Claim 1 A heat and pressure fuser apparatus comprising: a rotatably supported fuser belt; a pressure member adjacent a first portion of said belt wherein the first portion of said belt contacts said pressure member to form an extended nip therewith, said pressure member comprising a first rotatably supported roll in circumferential contact with said belt; and a heat source, adjacent a second portion of said belt said heat source comprises a second rotatably mounted roll in circumferential contact with the external surface of said belt and a heat generator, internal to said second roll, wherein said heat generator causes the temperature of the exterior surface of said second roll to elevate. ### Claim 2 (depends on 1) An apparatus according to claim 1, wherein said second rotatably mounted roll comprises a hollow aluminum cylinder supported at each end by rotatable bearings. ### Claim 3 (depends on 1) An apparatus as described in claim 1, wherein said belt has a relatively thick wall thickness. ### Claim 4 A heat and pressure fuser apparatus comprising: a rotatably supported fuser belt; a pressure member adjacent a first portion of said belt wherein the first portion of said belt contacts said pressure member to form an extended nip therewith, said pressure member comprising a rotatably supported pressure belt and a backup member supporting said pressure belt in the region of the extended nip; and a heat source, adjacent a second portion of said belt, wherein said heat source comprises a rotatably mounted roll in circumferential contact with the external surface of said belt and a heat generator, internal to said roll, wherein said heat generator causes the temperature of the exterior surface of said roll to elevate. ### Claim 5 A heat and pressure fuser apparatus comprising: a rotatably supported fuser belt, said belt is supported on a pair of spaced rolls, with the first portion of said belt spanning the space between said pair of rolls and the second portion of said belt spanning the space between said pair of rolls so that the first portion of said belt and the second portion of said belt are opposed from one another; a pressure member adjacent a first portion of said belt wherein the first portion of said belt contacts said pressure member to form an extended nip therewith, said pressure member comprising a first rotatably supported roll in circumferential contact with said belt; and a heat source, adjacent a second portion of said belt, said heat source comprises a second rotatably mounted roll in circumferential contact with the external surface of said belt and a heat generator, internal to said second roll, wherein said heat generator causes the temperature of the exterior surface of said second roll to elevate. ### Claim 6 A heat and pressure fuser apparatus comprising: a rotatably supported fuser belt, said belt comprising metal fibers enabling a high fusing pressure to be exerted on a sheet moved through an extended nip; a pressure member adjacent a first portion of said belt wherein the first portion of said belt contacts said pressure member to form the extended nip therewith; and a heat source, adjacent a second portion of said belt. ### Claim 7 A heat and pressure fuser apparatus comprising: a rotatably supported fuser belt, said belt comprising glass fibers enabling a high fusing pressure to be exerted on a sheet moved through an extended nip; a pressure member adjacent a first portion of said belt wherein the first portion of said belt contacts said pressure member to form the extended nip therewith; and a heat source, adjacent a second portion of said belt. ### Claim 8 A heat and pressure fuser apparatus comprising: a rotatably supported fuser belt, said belt comprising graphite fibers enabling a high fusing pressure to be exerted on a sheet moved through an extended nip; a pressure member adjacent a first portion of said belt wherein the first portion of said belt contacts said pressure member to form the extended nip therewith; and a heat source, adjacent a second portion of said belt. ### Claim 9 A heat and pressure fuser apparatus comprising: a rotatably supported fuser belt; a pressure member adjacent a first portion of said belt wherein the first portion of said belt contacts said pressure member to form an extended nip therewith; and a heat source adjacent a second portion of said belt, said heat source comprising a rotatably mounted roll in circumferential contact with the internal surface of said belt and a heat generator, internal to said second roll, wherein said heat generator causes the temperature of the exterior surface of said second roll to elevate. ### Claim 10 An electrophotographic printing machine in which a toner image is heat and pressure fused to a substrate by a fuser member, wherein the improvement comprises: a rotatably supported fuser belt; a pressure member adjacent a first portion of said belt wherein the first portion of said belt contacts said pressure member to form an extended nip therewith, said pressure member comprising a first rotatably supported roll in circumferential contact with said belt; and a heat source, adjacent a second portion of said belt said heat source comprises a second rotatably mounted roll in circumferential contact with said belt and a heat generator, internal to said second roll, wherein said heat generator causes the temperature of the exterior surface of said second roll to elevate. ### Claim 11 (depends on 10) The printing machine of claim 10, wherein said belt is supported on a pair of spaced rolls, with the first portion of said belt spanning the space between said pair of rolls and the second portion of said belt spanning the space between said pair of rolls so that the first portion of said belt and the second portion of said belt are opposed from one another. ### Claim 12 (depends on 10) The printing machine of claim 10, wherein said belt has a relatively thick wall thickness. ### Claim 13 (depends on 10) The printing machine of claim 10, wherein said second rotatably mounted roll comprises a hollow aluminum cylinder supported at each end by rotatable bearings. ### Claim 14 An electrophotographic printing machine in which a toner image is heat and pressure fused to a substrate by a fuser member, wherein the improvement comprises: a rotatably supported fuser belt; a pressure member adjacent a first portion of said belt wherein the first portion of said belt contacts said pressure member to form an extended nip therewith, said pressure member comprising a rotatably supported pressure belt and a backup member supporting said pressure belt in the region of the extended nip; and a heat source, adjacent a second portion of said belt, wherein said heat source comprises a second rotatably mounted roll in circumferential contact with said belt and a heat generator, internal to said second roll, wherein said heat generator causes the temperature of the exterior surface of said second roll to elevate. ### Claim 15 An electrophotographic printing machine in which a toner image is heat and pressure fused to a substrate by a fuser member, wherein the improvement comprises: a rotatably supported fuser belt, said belt comprises metal fibers enabling a high fusing pressure to be exerted on a sheet moved through an extended nip; a pressure member adjacent a first portion of said belt wherein the first portion of said belt contacts said pressure member to form the extended nip therewith; and a heat source, adjacent a second portion of said belt. ### Claim 16 An electrophotographic printing machine in which a toner image is heat and pressure fused to a substrate by a fuser member, wherein the improvement comprises: a rotatably supported fuser belt, said belt comprises glass fibers enabling a high fusing pressure to be exerted on a sheet moved through an extended nip; a pressure member adjacent a first portion of said belt wherein the first portion of said belt contacts said pressure member to form the extended nip therewith; and a heat source, adjacent a second portion of said belt. ### Claim 17 An electrophotographic printing machine in which a toner image is heat and pressure fused to a substrate by a fuser member, wherein the improvement comprises: a rotatably supported fuser belt, said belt comprises graphite fibers enabling a high fusing pressure to be exerted on a sheet moved through an extended nip; a pressure member adjacent a first portion of said belt wherein the first portion of said belt contacts said pressure member to form the extended nip therewith; and a heat source, adjacent a second portion of said belt. ### Claim 18 An electrophotographic printing machine in which a toner image is heat and pressure fused to a substrate by a fuser member, wherein the improvement comprises: a rotatable supported fuser belt; a pressure member adjacent a first portion of said belt wherein the first portion of said belt contacts said pressure member to form an extended nip therewith; and a heat source, adjacent a second portion of said belt, said heat source comprises a rotatably mounted roll in circumferential contact with the internal surface of said belt and a heat generator, internal to said second roll, wherein said heat generator causes the temperature of the exterior surface of said second roll to elevate.